不同修复方式对隐裂牙抗力影响的有限元分析

Investigation of Stress Distribution in the Cracked Tooth Restored with Different Restorative Materials and Designs:Finite Element Analysis

目的:探讨不同修复方式和材料对隐裂牙生物力学的影响。方法:通过三维建模软件建立上颌第一磨牙隐裂牙齿的模型,并在此模型上建立了4种修复体设计:二类洞、嵌体、高嵌体和全冠,应用了4种牙科材料:复合树脂(Filtek Z350)、树脂纳米陶瓷(Lava Ultimate)、二硅酸锂玻璃陶瓷(E.MAX)和二氧化锆全瓷(Duolink)。利用有限元分析软件(ANSYS17.0)对模型进行垂直加载和斜向加载,分析每个模型上修复体以及剩余牙体组织的应力分布。结果:隐裂牙在修复后可大幅降低局部应力集中,其中二类洞、嵌体在修复体边缘应力集中,隐裂表面应力较低;高嵌体、全冠可显著降低修复体周缘应力及隐裂表面的应力,与直接复合树脂和Lava Ultimate材料相比,E.MAX材料修复后裂纹表面的应力值较低。结论:从生物力学的角度来看,全冠、高嵌体以及E.MAX材料在缓解隐裂牙的应力集中方面更为有效。

Objective:Investigation of stress distribution in the cracked tooth restored with different restorative materials and designs.Methods:The model of cracked teeth of maxillary first molar was established by three-dimensional modeling software,and four kinds of restoration models were established based on this model.It includes four kinds of restoration designs:classⅡcavity,inlay,onlay and full crown.And four kinds of dental materials were used:composite resin,resin nano ceramics(Lava Ultimate),lithium disilicate glass ceramics(E.MAX),and zirconium dioxide.The model was loaded vertically and diagonally by ANSYS 17.0 software,and the stress distribution of the restoration and residual tooth tissue on each model was analyzed.Results:After restoration,the local stress concentration of cracked teeth can be greatly reduced,in which the classⅡcavity and inlay are concentrated at the edge of the restoration,and the stress on the cracked surface is lower,while onlay and full crown can significantly reduce the peripheral stress of the restoration and the stress on the cracked surface,and the stress value of the crack surface after E.MAX restoration is lower than that of direct composite resin and Lava Ultimate.Conclusion:Our results demonstrate that different restoration methods can significantly alleviate the stress concentration of cracked teeth,onlay,crown restoration and E.MAX materials are more effective in alleviating the stress concentration of teeth.